As Michael Gira's sextet returns to Edinburgh, we salute their latter-day revival

Since they were mostly reviled in their earliest incarnations, the revival of Swans was never liable to be a cosy nostalgia trip. Michael Gira’s fierce vision, too heady and intense even in the glory days of post-punk, may pursue an orchestrated majesty in this comeback, but the shuddering brutality of their first recordings is still audible beneath the complexity.

If Gira’s original version of Swans matured from a grinding, loud monotony into the more textured melodies of the 1990s, his influence is clear on the generation of post-rock bands, like Mogwai, who sprung up while Gira developed other projects. Yet the unexpected reformation of The Swans – and their two startlingly coherent albums – has Gira chasing a sophisticated ecstasy. Denying that the music points to any spirituality other than itself, he nevertheless encourages an immersion in sound, skilfully manipulating dynamics.

Although there are occasional nods to the past – some early tracks are revisited – Gira continues to follow a new muse. Elements of American folk and even funky repetition are filtered through an epic vision. Extending songs over instrumental work-outs that are taut and groove heavy, Swans in 2013 are heading towards a bracing fusion of psychedelic ferocity and minimalist compulsion.